SCIENCE CHINA Materials•2026•DOI: 10.1007/s40843-025-3558-4
The development of advanced titanium alloys capable of operating above 600 °C remains a critical challenge for aerospace propulsion systems, where conventional Ti alloys suffer from insufficient high-temperature strength and microstructural instability. Here, we propose a computationally driven design strategy for titanium-based medium-entropy alloys (MEAs) that integrates thermodynamic phase prediction with mechanistically informed strength modeling, enabling systematic exploration of the Ti-Nb-Al-Cr quaternary system. The optimized Ti70Nb10Al15Cr5 MEA exhibits exceptional performance metrics: 18% room-temperature ductility (as-cast), a yield strength of 520.7 MPa at 650 °C (post-aging), and an ultralow density of 4.76 g/cm3 (45% lighter than Inconel 718). Microstructural characterization reveals a metastable single-phase BCC structure in the as-cast state, which transforms into a BCC/Ti3Al dual-phase system upon aging, with temperature-dependent precipitate morphology and phase stability. The alloy demonstrates superior high-temperature strength retention up to 900 °C (>80 MPa yield strength), outperforming commercial titanium alloys (e.g., Ti-1100, TG6) and bridging the performance gap between conventional Ti alloys and nickel-based superalloys. This work establishes a multi-criteria design paradigm for entropy-engineered alloys, offering a viable pathway to lightweight, high-temperature structural materials for next-generation aerospace applications.
Chinese Journal of Environmental Engineering•2026•DOI: 10.12030/j.cjee.202506005
The escalating generation of medical waste, driven by healthcare expansion and frequent medical activities, poses significant environmental and public health risks. Under the framework of ecological civilization, China is developing a comprehensive policy system for medical waste treatment and disposal, yet the current framework remains nascent and exhibits inconsistencies between national and local policies. This study systematically analyzes the status of national and local policies from 2003 to 2024, collecting 413 policy documents (166 from national ministries and 247 from provincial governments). The analysis examines temporal evolution, regional distribution, and policy focus, alongside the influence of medical waste output, treatment technologies, facility infrastructure, and major epidemic responses. Findings reveal distinct policy phases: initial self-disposal, exploratory management, foundational system building, and rapid development. Regional disparities are pronounced, with eastern coastal areas showing more advanced policies due to greater technical and financial resources. The surge in medical waste, particularly during the COVID-19 pandemic, underscores the need for enhanced regulatory guidance. Non-incineration technologies are gaining traction for their environmental and cost benefits, and facility coverage has improved but remains uneven. The study proposes five policy principles to foster technological innovation and industrial upgrading, ensuring safe medical waste management and environmental protection.
SCIENCE CHINA Materials•2026•DOI: 10.1007/s40843-025-3464-4
Photocatalytic conversion of atmospheric CO2 (0.03%) into multi-carbon fuels remains a grand challenge due to the high energy barrier of C–C coupling and the low concentration of CO2. Here, we report the construction of multiple metal pair sites on metal oxide nanosheets to steer C–C coupling, enabling efficient photoreduction of air-concentration CO2 to ethane (C2H6). As a prototype, Au nanoparticles were anchored on Bi4Ti3O12 nanosheets (Au-Bi4Ti3O12). High-resolution transmission electron microscopy and X-ray photoelectron spectroscopy confirmed the formation of Au-Ti metal pair sites at the interface. In situ Fourier transform infrared spectroscopy revealed the presence of *OCCOH intermediate on Au-Bi4Ti3O12 during CO2 photoreduction, which was absent on pristine Bi4Ti3O12. Density functional theory calculations showed that the Gibbs free energy for *CO–COH formation on Au-Bi4Ti3O12 is 2.23 eV, significantly lower than that on Bi4Ti3O12 (3.59 eV), indicating facilitated C–C coupling. Consequently, Au-Bi4Ti3O12 exhibited a C2H6 evolution rate of 2.58 μmol g−1 h−1 under 0.03% CO2, whereas Bi4Ti3O12 produced only C1 products (CO and CH4). This work demonstrates the first single-catalyst photoreduction of atmospheric CO2 to C2H6, highlighting the effectiveness of engineered multiple active sites in overcoming the C–C coupling bottleneck.
New Carbon Materials•2026•DOI: 10.1016/S1872-5805(26)61113-4
Porous pyrolytic carbon (PPyC) serves as the buffer layer in TRi-structural ISOtropic (TRISO) fuel particles, providing storage for fission gases, preventing damage to outer layers, and absorbing stresses caused by fuel-kernel swelling. However, the changes of PPyC micro- and meso-structure at high temperatures remain insufficiently understood. In this study, PPyC fabricated by chemical vapor deposition was heat-treated from 1200 to 1600 °C and characterized across atomic-to-mesoscopic scales. Results show that the structure changes with temperature with a transition at approximately 1400 °C. Below 1400 °C, a decrease in Raman ID/IG ratio, narrowing of the graphite diffraction peak, and increased sp2 hybridization indicate progressive ordering associated with defect redistribution. Concurrent decreases in true density and mesopore volume, together with increased closed porosity, are consistent with partial conversion of open pores into closed pores. Above 1400 °C, increased ID/IG ratio, broadening of the diffraction peak near the rhombohedral graphite (101) reflection, and transition regions between crystalline and amorphous material observed by TEM indicate increasing structural disorder. Meanwhile, initially distinct PPyC particle boundaries blur and merge into broad, plate-like domains. Subsequent decrease in closed porosity and increase in mesopore surface area are consistent with partial connection of closed pores to the open-pore network. This work shows that intrinsic coupling between atomic-scale structural change and mesoscale pore connectivity provides a basis for assessing high-temperature structural stability of PPyC in TRISO fuel particles.
Journal of Fuel Chemistry and Technology•2026•DOI: 10.1016/S1872-5813(26)60657-3
Fe-Mn catalysts have attracted considerable attention for industrial Fischer-Tropsch synthesis (FTS) due to their ability to modulate product spectra. Carbon adsorption and permeation on catalyst surfaces are critical elementary steps in the in situ formation of active iron carbide phases. Here, density functional theory (DFT) calculations systematically investigate the atomistic structures, thermodynamic stabilities, and electronic properties of carbon-deposited Fe-Mn alloy surfaces at the early stage of carburization. These surfaces exhibit distinct thermodynamic sensitivity to carbon atoms adsorbed on the surface and permeating into interstitial sites. By combining DFT with minima-hopping structural searches, we demonstrate that the initial stage of carbon permeation cannot trigger surface reconstruction to form iron carbide phases. The addition of manganese thermodynamically hinders carbon permeation. Although deposited carbon atoms modulate the electronic structure of metals, manganese retards the shift of d-band centers toward those of bulk iron carbide phases. This study provides atomic-scale insight into the in situ evolution of Fe-Mn catalyst surfaces during carbon deposition, indicating that manganese promoter has a noticeable effect on carbon permeation.
Environmental Chemistry•2026•DOI: 10.7524/j.issn.0254-6108.2026030601
Bisphenol A (BPA), a high-volume industrial chemical, is implicated in neurotoxicity and chronic neurodegenerative diseases. This study integrates network toxicology, molecular docking, and molecular dynamics simulations to systematically delineate the common mechanisms linking BPA to Alzheimer's disease (AD), Parkinson's disease (PD), and Huntington's disease (HD). Using the human astrocyte cell line SVGP12 as an in vitro model, we identified six key toxic functional proteins—TP53, HSP90AA1, HSP90AB1, INS, BCL2, and AKT1—that mediate BPA's effects across these diseases, with BCL2 emerging as the most central node. Experimental validation demonstrated that BPA induces oxidative stress and cell cycle arrest, suppresses the INS-AKT1-BCL2 anti-apoptotic pathway, and activates the TP53-HSP90 pro-apoptotic pathway, culminating in mitochondrial apoptosis of astrocytes and disruption of neural microenvironment homeostasis. These findings reveal a convergent mechanism by which BPA accelerates neurodegeneration, filling a critical gap in understanding BPA's role in AD, PD, and HD. The study provides a novel theoretical framework and experimental evidence for BPA neurotoxicity risk assessment and informs preventive and therapeutic strategies for BPA-related neurodegenerative disorders.
SCIENCE CHINA Materials•2026•DOI: 10.1007/s40843-026-4075-1
Titanium alloys, such as Ti-6Al-4V (TC4), are indispensable in aerospace, biomedical, and advanced manufacturing due to their high specific strength, corrosion resistance, and biocompatibility. However, their inherent strength-ductility trade-off and limited stiffness hinder next-generation lightweight structural applications. Traditional ceramic reinforcements (TiC, TiB2, SiC) improve strength but introduce brittleness and interfacial incompatibility, degrading plasticity and fatigue resistance. Graphene, with theoretical strength ~130 GPa and Young's modulus ~1 TPa, offers a promising two-dimensional reinforcement. This review systematically examines graphene-reinforced titanium matrix composites (TMCs), focusing on the intrinsic relationship between preparation, microstructure, and properties. Key preparation routes include powder metallurgy and additive manufacturing, with challenges in achieving uniform dispersion and controlling interfacial reactions. Recent studies demonstrate that surface modification and process optimization can form an ideal interface structure comprising a nano-TiC layer and residual graphene. Even at low graphene additions, synergistic strengthening mechanisms—load transfer, fine-grain strengthening, and Orowan dislocation bypass—significantly enhance strength, hardness, and wear resistance while preserving ductility. This review consolidates critical theoretical and experimental findings, offering guidance to overcome technological bottlenecks and promote engineering applications of graphene-reinforced TMCs.
SCIENCE CHINA Materials•2025•DOI: 10.1007/s40843-025-3433-x
The design of photosensitizers that generate hydroxyl radicals (·OH) from water and achieve efficient charge separation (CS) is critical for hypoxic tumor photodynamic therapy (PDT). However, such ·OH photo-generators are scarcely reported, particularly those based on simple D-π-A scaffolds. This work presents TPE-SPyCx@BSA, constructed via co-assembly of a series of D-π-A tetraphenylpyridine salts (TPE-SPyCx) with bovine serum albumin (BSA), which initiates photocatalytic water oxidation to ·OH and enables efficient charge separation for oxygen-independent PDT. Electron paramagnetic resonance (EPR) trapping confirmed high-efficiency ·OH generation, and isotope tracing experiments revealed that the oxygen source of ·OH originates exclusively from H2O. The calculated valence band (VB) potential of TPE-SPyCx@BSA meets the thermodynamic conditions for ·OH production via water oxidation. Transient absorption spectra deciphered that the charge-separated state is realized after co-assembly, ensuring electron transfer to generate ·OH via an oxygen-independent pathway. TPE-SPyCx@BSA exhibited superb photocytotoxicity even under severe anoxic conditions and excellent antitumor efficacy in in vivo mouse models. This work provides a strategy for constructing oxygen-independent photodynamic agents, opening an avenue for effective PDT against hypoxic tumors.
SCIENCE CHINA Materials•2025•DOI: 10.1007/s40843-025-3577-4
Broad-absorbing materials, characterized by tunable absorption across ultraviolet to mid-infrared spectral regions, have emerged as a crucial class of optoelectronic materials. Significant advances have been achieved in organic and inorganic materials; however, current enhancement strategies remain largely platform-specific and are not guided by a unified physical framework. To address this gap, this review introduces a three-factor physical model grounded in the theory of transition probability, thereby providing a consistent theoretical basis for understanding how electronic transitions are modulated across orbital, vibrational, and spin dimensions. Structure-mechanism-performance relationships are systematically examined in classic material platforms. In addition, the contributions of external-field enhancement mechanisms, such as plasmonic resonance, to spectral broadening and local-field enhancement are discussed. Based on clear mechanistic insight and targeted materials design, recent advances in integrating broad-absorbing materials into broadband photodetectors are highlighted, emphasizing their practical relevance. The review examines the three core challenges and mechanism-driven design strategies for high-performance broadband optoelectronic systems, providing an instructive outlook for future advancements.
SCIENCE CHINA Materials•2025•DOI: 10.1007/s40843-025-3563-0
Organic cocrystals have become increasingly prevalent in various research domains owing to simple preparation, cost-effectiveness, and highly tunable properties. Strong charge transfer (CT) interactions in cocrystals render them promising candidates for high-efficiency photothermal conversion materials. However, the majority of reported organic photothermal cocrystals exhibit planar and rigid π-conjugated structures, which restrict molecular vibrations while simultaneously impeding non-radiative dissipation processes—ultimately hindering the enhancement of photothermal conversion performance. Herein, we design a novel non-planar photothermal NMTQ cocrystal, which shows a broadband absorption range of 220–2000 nm and high photothermal conversion efficiencies from ultraviolet (UV) to near-infrared (NIR)-II region. Quantum chemical calculations demonstrate that the distorted butterfly-like conformation in NMTQ is conducive to non-radiative transitions via higher non-adiabatic couplings (NACs) and lower spatial overlap integral (Sr). An interfacial solar evaporation system was constructed using NMTQ cocrystals, achieving an evaporation rate of 2.158 kg m−2 h−1 with 94.96% solar-to-vapor conversion efficiency under 1 Sun irradiation. The photothermal platform demonstrated simultaneous contaminant removal functionality, establishing a sustainable strategy for clean water production through rational photothermal material design.